将所有查询结果转储到plsql块内的文件中 [英] Dump all query results in file inside a plsql block

问题描述

我正面临以下问题.我想执行查询并将所有结果导出到文件中.我的查询另存为varchar2类型，我可以立即对其执行并给我所有结果.现在，这些结果如何将它们全部转储到文件中.我不想从查询或其他任何内容中选择特定的列名.这就像大量结果的批量收集并将其转储到文件中一样.这是我正在处理的一些伪代码:

I am facing the following issue. I want to execute a query and export all the results in a file. My query is saved as in varchar2 type and i can execute immediate on it and give me all the results. Now these results how can i dump them all in a file. I don't want to select specific column names from the query or anything. It is like a bulk collect of many results and dump them to a file. Here is some pseudocode of what i was working on:

这是一种行不通的方法

Declare
filehandle1 UTL_FILE.FILE_TYPE;
myquery     varchar2(4000) := 'Select column1'||'~'||'Column2'||'~'||' from mytable';
Begin
filehandle1 := UTL_FILE.FOPEN ('MYDIR','mydata','W');
    FOR emp IN (execute immediate (myquery)) LOOP --This part of course is not working
        UTL_FILE.PUT (filehandle1, emp.*);        --i dont want to write each column
    END LOOP;                                     --i have the columns and formatting ready of the query
    UTL_FILE.FCLOSE (filehandle1);
End;

这又是另一种行不通的方式

This is another way again that will not work

Declare
    filehandle1 UTL_FILE.FILE_TYPE;
    myquery     varchar2(4000) := 'Select column1'||'~'||'Column2'||'~'||' from mytable';
    Begin
    filehandle1 := UTL_FILE.FOPEN ('MYDIR','mydata','W');
    UTL_FILE.PUT (filehandle1, myquery); --i want just to execute the query and write 
    UTL_FILE.FCLOSE (filehandle1);       --everything in the file
    End;

我怎么能得到所有东西并将它们扔到文件中?另外，我必须在plsql块中完成此操作，因此我无法将其假脱机处理

How can i just get everything and throw them in the file? Also i this has to be done in a plsql block therefore i cannot spool them Thanks in advance

推荐答案

您可以在游标上循环:

declare
  filehandle1 utl_file.file_type;
  myquery varchar2(4000) := 'select column1 ||''~''|| column2 from mytable';
  mycursor sys_refcursor;
  myresult varchar2(4000);
begin
  filehandle1 := utl_file.fopen ('D42', 'mydata', 'w');
  open mycursor for myquery; 
  loop
    fetch mycursor into myresult;
    exit when mycursor%notfound;
    utl_file.put_line(filehandle1, myresult);
  end loop;
  close mycursor;
  utl_file.fclose(filehandle1);
end;
/

或更简单地说，如果您不需要查询为字符串(例如，我不确定您是否实际上是从另一个表中获取它，否则我不确定为什么要使用它作为varchar2变量):

Or more simply if you don't need the query to be a string (I'm not sure if you're actually getting it from another table, for example, otherwise I'm not sure why you'd have it as a varchar2 variable):

declare
  filehandle1 utl_file.file_type;
begin
  filehandle1 := utl_file.fopen ('D42', 'mydata', 'w');
  for myrec in (select column1 ||'~'|| column2 as result from mytable)
  loop
    utl_file.put_line(filehandle1, myrec.result);
  end loop;
  utl_file.fclose(filehandle1);
end;
/

如果我将表创建并填充为:

If I create and populate the table as:

create table mytable (column1 number, column2 varchar2(10));
insert into mytable (column1, column2) values (1, 'First');
insert into mytable (column1, column2) values (2, 'Second');

然后使用其中任何一个，mydata文件包含:

Then with either of those, the mydata file contains:

1~First
2~Second

如果要显式使用批量收集，可以执行以下操作:

If you want to explicitly use bulk collect you can do this:

declare
  filehandle1 utl_file.file_type;
  myquery varchar2(4000) := 'select column1 ||''~''|| column2 from mytable';
  mycursor sys_refcursor;
  myresults sys.odcivarchar2list;
begin
  filehandle1 := utl_file.fopen ('D42', 'mydata', 'w');
  open mycursor for myquery; 
  loop
    fetch mycursor bulk collect into myresults limit 100;
    for idx in myresults.first..myresults.last loop
      utl_file.put_line(filehandle1, myresults(idx));
    end loop;
    exit when mycursor%notfound;
  end loop;
  close mycursor;
  utl_file.fclose(filehandle1);
end;
/

这篇关于将所有查询结果转储到plsql块内的文件中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！